(1) Field of the Invention
The present invention relates to an improved dental prophylaxis (prophylactic) cup and method of use of the cup. In particular, the present invention relates to an improved dental prophylaxis cup that is molded from a medical grade silicone elastomer (flexible silicone polymer) incorporating an abrasive, preferably a coarse pumice material. The incorporated pumice is a dental cleaning and polishing agent and eliminates the need for applying any external cleaning paste to the prophylaxis cup.
(2) Prior Art
The prior art has described various types of devices for securing a cleaning device such as a dental prophylaxis cup to a dental handpiece. The dental handpiece is a mechanical instrument that is used to rotate the cup for the teeth cleaning procedure. Most of the prior art prophylaxis cups are formed from an elastomeric material, such as a rubber compound, Even when the working end of the cup is provided with a raised or ribbed configuration, the elastomeric cups alone are not particularly suited for cleaning stains and plaque from teeth and from within gingival crevices or sulci. To facilitate the cleaning process, an abrasive cleaning paste is required. The paste is applied to the prophylaxis cup by one of two methods. The most universally used method requires that the cup be dipped into a paste source to coat the working end of the prophylaxis cup with the paste. However, the paste is quickly worked off the prophylaxis cup and the cleaning paste must be frequently applied to the working end of the cup during the teeth cleaning. Illustrative to this type of device is U.S. Pat. Nos. 1,620,990 to Brothers; 1,644,465 to Chott; 1,837,938 to Young; 2,093,006 to Chott; 2,093,007 to Chott and 4,259,071 to Warden et al.
In the second method, which is not in service, the prophylaxis cup is provided with a central passage system for introducing a dental cleaning paste to the working end of the cup. The paste is stored in a storage compartment in the dental handpiece tool and is pumped through the passage system to the working end of the cup during the teeth cleaning procedure. The dental handpiece tool must then be sterilized between patients and the paste storage compartment must be periodically refilled with cleaning paste. Illustrative of this type of device is U.S. Pat. Nos. 3,977,083 to Leslie et al; 3,977,084 to Sloan; 4,097,995 to Danne et al and 4,266,933 to Warden et al.
The prior art has also shown rotatable discs with embedded abrasive material that are used for dental hygiene. Illustrative of this prior art is U.S. Pat. No. 4,601,661 to Du Be' et al.
U.S. Pat. No. 4,636,171 to Martin describes a polishing tip (FIG. 2) made of a silicone rubber material mounted on a mandrel driven by a dental engine. The polishing tip is described as being filled with an abrasive material such as aluminum oxide or zirconium flour, to produce a self-contained abrasive unit. In FIG. 3, Martin describes a polishing cup with a conical recess at a working end of the cup. The polishing cup does not contain an abrasive material, but instead requires a paste incorporating an abrasive. This signifies one of the problems overcome by the present invention. While silicone rubber polishing tips (FIG. 2) impregnated with an abrasive are known in the prior art, until the present invention, a silicone elastomeric prophylaxis cup incorporating an abrasive has not been invented. The reason for this is that it is difficult to mold an abrasive filled silicone elastomeric cup having a rim formed by a conical recess of the cup that will hold up during the teeth cleaning procedure. Also, the mandrel and dental engine have a straight construction along a longitudinal axis of the mandrel and engine and most tooth surfaces are inaccessible using this engine and polishing tip.
Finally, the prior art has described abrasive filled dental prophylaxis cups. U.S. Pat. No. 3,789,462 to Reich describes an abrasive-filled dental cup formed from a urethane elastomer. The polyurethane elastomer consists essentially of tolylene diisocyanate (TDI) endcapped polytetrahydrofuran cured with 4,4'- methylene bis(o-chloroaniline). The elastomer has 25-40 percent by weight of pumice added to the elastomer as a dental abrasive which obviates the use of a prophylaxis dental paste with the prophylaxis cup. The prophylaxis cup is formed as a shaped body molded on a mounting member comprised of a mandrel and a threaded shaft for removably mounting the cup on a dental handpiece and thus the design is different. The prophylaxis cup is not removeable from the mounting member. Polyurethanes are not suitable for use in the mouth. The precursors are suspected carcinogens as shown by the Merck Index 11th edition (1989) and any residual monomers would have the potential for toxicity.
There is therefore a need for a reliable dental prophylaxis cup for cleaning plaque and stains from teeth and gingival crevices or sulci that eliminates the need for a dental cleaning paste or material to be applied to the prophylaxis cup and which is removeably mounted on a "dental button member" in a dental handpiece. The prophylaxis cup of the present invention satisfies this need by providing a prophylaxis cup formed of a medical grade silicone elastomer, incorporating a coarse pumice as the cleaning agent. The pumice eliminates the need for a cleaning paste to be used during the teeth cleaning procedure which is a significant improvement over the prior art prophylaxis cups that require a dental cleaning paste. During the prophylaxis procedure, the paste will splatter. These extra-oral splatterings include blood and saliva which contain pathogenic, disease causing organisms. Thus, by eliminating dental cleaning paste, the prophylaxis cup of the present invention enhances infection and disease control for both the dentist or hygienist, and the patient. Rinsing is also eliminated. Elimination of splattering also increases the useful life of the dental handpiece because the pumice abrasive does not infiltrate into the gears of the handpiece to wear them.